Myelodysplastic syndromes (MDS) are myeloid neoplasms characterized by clonal proliferation of hematopoietic stem cells, recurrent genetic abnormalities, myelodysplasia, ineffective hematopoiesis, peripheral-blood cytopenia, and a high risk of evolution to acute myeloid leukemia (AML).
Diagnostic Criteria for Myeloid Neoplasms with Myelodysplasia and Precursor Conditions for Myelodysplastic syndromes red 5px solid(MDS)
| Disorder | Diagnostic Criteria |
| Myeloid neoplasms with myelodysplasia | |
| MDS | Persistent cytopenia in one or more peripheral-blood cell lineages and morphologic dysplasia (≥10% dysplastic cells) in one or more bone marrow cell lineages; on the basis of morphologic and cytogenetic abnormalities, MDS are categorized into the following subtypes: MDS with single-lineage dysplasia MDS with multilineage dysplasia MDS with ring sideroblasts and single-lineage dysplasia or multilineage dysplasia MDS with isolated del(5q) MDS with excess blasts type 1 or type 2 MDS, unclassifiable |
| Myelodysplastic–myeloproliferative neoplasms | Myeloid neoplasms with clinical, laboratory, and morphologic features that overlap those of MDS and myeloproliferative neoplasms; myelodysplastic–myeloproliferative neoplasms are divided into the following subtypes: Chronic myelomonocytic leukemia BCR-ABL1–negative atypical chronic myeloid leukemia Myelodysplastic–myeloproliferative neoplasm with ring sideroblasts and thrombocytosis Juvenile myelomonocytic leukemia |
| Therapy-related myeloid neoplasms | MDS, myelodysplastic–myeloproliferative neoplasms, and acute myeloid leukemia that occur as late complications of chemotherapy or radiotherapy |
| MDS precursor conditions | |
| Clonal Hematopoiesis of Indeterminate Potential (CHIP) | Normal peripheral-blood cell counts with a somatic mutation, at a variant allele frequency of at least 2%, in a gene that is recurrently mutated in myeloid neoplasms‡ |
| Clonal Cytopenia of Undetermined Significance (CCUS) | Unexplained cytopenia in one or more peripheral-blood cell lineages; a somatic mutation, at a variant allele frequency of at least 20%, in one or more genes that are recurrently mutated in myeloid neoplasms; and insufficient WHO criteria for a diagnosis of MDS, essentially because of lack of overt dysplasia (<10% dysplastic cells in any bone marrow cell lineage), excess blasts, and MDS-defining chromosomal abnor-malities § |
‡ Persons with CHIP may have increased values for red-cell distribution width.
§ Although a variant allele frequency of at least 2% was initially suggested for the diagnosis of CCUS, the available evidence indicates that a higher cutoff point (20%) should be used to identify clinically significant clonality.
References:
- Cazzola M. Myelodysplastic Syndromes. N Engl J Med. 2020 Oct 1;383(14):1358-1374. [Medline]
- Shreve J, Nazha A. Novel Prognostic Models for Myelodysplastic Syndromes. Hematol Oncol Clin North Am. 2020 Apr;34(2):369-378. [Medline]
Created Nov 26, 2020.
